1. Field of the Invention
This invention relates to micro-fibers-generating conjugate fibers. More particularly it relates to micro-fibers-generating conjugate fibers from which micro-fibers are generated by removing a part of components constituting the conjugate fibers, and a woven fabric or non-woven fabric using the same.
2. Description of the Related Art
Recently, as high-class and diversified clothes have been desired, improvement in feeling of fibers by way of making fibers very fine has been attempted, and further as use applications of synthetic paper, non-woven fabric, etc. are developed, a process for producing micro-fibers has been also desired to be developed. Among micro-fibers-generating fibers, those of the so-called island-in-sea type fibers are very useful and it is well-known that a number of products using the same are commercially available.
Among the island-in-sea type, micro-fibers-generating fibers, particularly those wherein the island-in-sea structure is relied on a polymer blend, as disclosed in Japanese patent publication No. Sho 47-37648/1972, are prepared by blending different kinds of polymers constituting the respective components of island and sea, melt-spinning the resulting blend and removing the sea component with a solvent to leave only the island component. In such fibers, the blending proportion of the sea component should be large for keeping the independency of the island component. However, the sea component is used for temporarily binding a bundle of micro-fibers, and is to be finally removed. Hence the binding component cannot be a reinforcing component. So, the micro-fibers-generating fibers of this type could not have a high tenacity. Further, the bundle of micro-fibers as a remaining island component obtained by removing the sea component from the island-in-sea type micro-fibers-generating fibers has a low tenacity.
Further, as to the spinnability of fibers obtained by subjecting different kinds of polymers to composite spinning so as to give an island-in-sea structure as disclosed in Japanese patent application laid-open No. Sho 60-21904(1985), since the spinnability of the sea component is very often inferior, the spinnability of the island-in-sea type fibers is inferior, too. Further, in the case of fibers the island-in-sea components of which are of a polymer blend, since polymers having different properties from each other are blended, a satisfactory spinning stability cannot be obtained. So, the polymer is extruded from spinning nozzles in a thick and fine form and the extrudate is liable to break like raindrops.